Self-compensating adjustable keeper

ABSTRACT

A keeper assembly for use with a latch to hold a chassis or the like in position on a support in which a first member on the support adjustably receives a second member which slidably carries a keeper pin which is spring-loaded to retracted position with a predetermined force to permit a latch hook on the chassis to engage the keeper pin and to move it against the action of the spring to drive the chassis to a home position on the support and to permit adjustment of the second member relative to the first to vary the initial position of the keeper pin without changing the predetermined load provided by the spring.

United States Patent 1 1 [111 3,910,669

MacMaster Oct. 7, 1975 [5 SELF-COMPENSATING- ADJUSTABLE 3,575,482 4/1971 MacMaster et al. 339 75 M KEEPER FOREIGN PATENTS OR APPLICATIONS Inventor: Edward MacMaster, New Milford, 77,088 11/1917 Switzerland 292/341.15

[731 Assignee: Rex Chainbelt Inc., Milwaukee, Wis. Primary Examiner-Joseph M Attorney, Agent, or Firm-Shemer & OConnor [22] Filed: Nov. 12, 1973 [21] Appl. No.: 414,849 [57] ABSTRACT Related s Application Data A keeper assembly for use with a latch to hold a chas- [63] Continuation of Ser No 286 327 p 5 1972 sis or the like in position on a support in which a first abandoned, which a 'comirmation member on the support adjustably receives a second 107,755 Jan 19 1971 abandoned member which slidably carries a keeper pin which is spring-loaded to retracted position with a predeter- 52 US. (:I. 339/75 R; 312/320 mined feree to Permit a leteh heek Oh the ehessis to 51 Int. (:1. H01R 13/54 engage the keeper P and to move it against the [58] Field 61 Search 339/75, 91; 292/341.15, of the Spring to drive the chassis to a home P 292/34L18; 312/320 tion on the support and topermit adjustment of the second member relative to the first to vary the initial [56] References Cited position of the keeper pin without changing the prede- UNITED STATES PATENTS termined load provided by the spring. 2,926,056 2/1960 Newcomer, Jr. et al. 312/320 6 Claims, 6 Drawing Figures US. Patent 0a. 7,1975 SheetlofZ 3,910,669

FL i

INVEN TOR.

Q4 Ea wora Maclfldsfer g BY 4 5e 60 M U.S. Patent Oct. 7,1975 Sheet 2 of2 3,910,669

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1 SELF-COMPENSATING ADJUSTABLE KEEPER This is a continuation of application Ser. No. 286,327, filed Sept. 5,1972, which application was a continuation of application Ser. No. 107,755 filed Jan. 19, 1971, both now abandoned.

BACKGROUND OF THE INVENTION There are known in the priorlart latches for use with installations such as an electronic chassis which is slid along a rack on a mounting panel toward a home position. As the latch .moves into its home position, a plurality of pin connectors are driven into an electrical receptacle in the panel. 7 v

Latch assemblies of the typedescribed above include a handle secured to the chassis and a lever pivoted on the handle and provided with a hook adapted to engage a keeper pin on the panel as the chassis moves towards its home position. The lever is rotated from an open to a closed position to engage the keeper pin to drive the chassis into its home position. Further in the prior art the keeper pin is mounted for sliding movement in a direction perpendicular to its axis and is spring biased toward a retracted position. When the lever is operated in the manner described, the spring holds the chassis in its closed position with a predetermined force. The spring loading of the keeper pin compensates for a certain amount of rack, chassis and connector tolerance buildup. A spring is employed to take up any overload owing to jamming and to reduce the effect of vibration.

I have found that in many installations in the prior art the tolerance buildup which must be accommodated is greater than that which can be taken up by the spring loaded keeper arrangement of the prior art. Moreover, owing to space considerations the springs of keeper assemblies of the prior art cannot be made sufficiently large to accommodate the tolerance buildup while retaining the desired preload afforded by the spring. I have invented a self-compensating adjustable keeper assembly which overcomes the limitation described above, of keeper assemblies of the prior art. By use of my self-compensating adjustable keeper assembly the initial position of the keeperpin can be changed with out changing the predetermined force with which the chassis is held in its home position by the spring which loads the keeper pin. It can accommodate a greater tolerance buildup than that which can be accommodated by keeper assemblies of the prior art. It is simple and is relatively inexpensive to construct for the result achieved thereby. V

SUMMARY OF THE INVENTION One object of my invention is to provide a selfcompensating adjustable keeper assembly especially adapted for use with a chassis latch or the like.

Another object of my invention is to provide a keeper pin assembly which permits adjustment of the initial position of thekeeper pin withoutchanging the preloading forceof the keeper springi,

An additional object of myinventio n is to provide interchangeability between various chassis and various racks without further adjustment of the keeper assembly other than the initial installation setting accomplishedfor the basiechassis and rack configuration.

A further object of myinven tion is to providea selfcompensating adjustable keeper assembly which is simple in construction and relatively inexpensive to manufacture.

Other and further objects of my invention will appear in the following description.

In general my invention contemplates the provision of a self-compensating keeper assembly for use with a chassis latch or the like to hold a chassis in position on a rack in which a first member secured to a bracket on the rack adjustably receives a second member which slidably supports the keeper pin for movement in a direction perpendicular to the longitudinal axis of the pin with a preloaded spring biasing the keeper pin to a retracted position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 is a fragmentary side elevation of a latch and keeper including my self-compensating adjustable keeper illustrating the operation of the parts as the chassis moves towards its home position.

FIG. 5 is a fragmentary side elevation of a latch and keeper arrangement incorporating my selfcompensating adjustable keeper illustrating the position of the parts with the chassis in its home position.

FIG. 6 is a sectional view of my self-compensating adjustable keeper.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings I have shown a handle and latch assembly indicated generally by the reference character 10 carried by an electronic chassis 12 or the like for cooperation with. a keeper assembly indicated generally by the reference character 14 secured to a chassis housing or rack 16 in a manner to be described.

The handle and latch assembly 10 which is of a type known in the art includes generally a U-shaped handle secured to the chassis 12 by means of screws or the like 20 which pass through the chassis and into the legs 22 and 24 of the handle. Handle 18 is formed with a recess 26 for receiving a lever 28 pivotally supported on a pin 30 for movement between an open or unhoused position out of the recess 26 and a closed or housed position in the recess.

I provide the lower end of the lever 28 with a hook 32 adapted to cooperate with a keeper pin to be described herein below. A pin 36 on leg 22 pivotally supports a trigger 34 which is normally urged by a spring ,38 t'oa position at which a catch 40 on the trigger engages in a recess 42 in the upper end of handle 28 to hold the handle in its closed position. Trigger 34 can be f moved against the action of spring 38 to release lever out of the recess 26 when the trigger is operated to release the lever. My self-compensating adjustable keeper assembly 14 shaped bracket 50 having a base 52. A rod 54 secured to the base 52 by any suitable means as by screw threads or the like extends into a first housing half 56 provided with external threads 58. I thread the first housing half 56 into a second housing half 60 having internal threads 62 to adjust the position of the half 56 along the length of the half 60.

A threaded stud 64 secured to the housing half 60 is inserted into a bracket 68 and is retained in position thereon by means of a nut 66. Bracket 68 in turn may be secured toor form an integral part with the rack 16.

I thread a screw 70 into an axial bore in rod 54 to hold a head 72 in position on the rod 54. Before assembling the screw 70 and head 72 on the rod 54 I place a spring 76 over the rod. When these parts have been assembled in the manner described spring 76 holds pin 48 in a retracted position with relation to the housing half 56 with a predetermined force.

In operation ofthe latch and assembly in conjunction with my self-compensating adjustable keeper 14, assuming that the lever 28 is in its housed position and that the chassis is in its home position with reference to the tack 16, in order to remove the chassis 12 from the rack 16 trigger 34 is rotated in a clockwise direction around its pivot pin 36 to release the handle 28. This may be accomplished either by exerting pressure with the forefinger under the lower edge of trigger 34 or by pushing up on thumbpiece 44. When that occurs spring 46 causes the lever 28 to spring outwardly to an accessible position. Next the lever 28 is grasped and rotated around its pin 30 in a counter-clockwise direction from the position shown in FIG. 2 to the position shown in FIG. 3. In the course of this movement hook 32 engages the base 52 of bracket 50 to draw the chassis l2 and the pin connectors (not shown) carried thereby out of the the receptacle in the rack. The chassis 12 may then be completely removed from the rack 16. When it is removed the lever 28 may be returned to its housed position if-convenient and the chassis may be carried by means of the handle 18. It will be appreciated, of course, that handle 18 permits the chassis to be carried even though the lever 28 is not housed.

, To reinstall the chassis 12 in the rack 16 the chassis is slid along the rack until the panel is a few inches from the rack frame. If the lever 28 is housed it is now released by operating the trigger to permit the lever to move to its fully open position. With the lever open the chassis is slid further into the rack until the lever strikes the keeper pin 48. The arrangement is such that movement of the chassis toward the back of the rack is arrested at this point to prevent impact damage to the connectors at the rear of the chassis. Next the lever 28 is rotated in a clockwise direction to cause hook 32 to engage the keeper pin 48 in the manner shown in FIG 4. The lever 28 then is rotated to its fully-closed posiincludes a keeper pin 48 supported in a generally U- tion. As it moves into that position the connectors at I Should it become necessary or desirable for any reason in a particular installation to change the initial position of the pin 48 without affecting the preload of spring 76 the position of the adjustable housing half 58 with relation to the 'fixed'housing half 60 may readily be varied. This can be accomplished by rotating the hexagonal portion of housing half 56 while holding the hexagonal portion of housing half 60 for a distance such, for example, as that indicated by b in FIG. 5.

It will be seen that I have accomplished the objects of my invention/I have provided a self-compensating adjustable keeper assembly especially adapted for use with an electronic chassis latch or the like. My keeper assembly permits the initial position of the keeper pin to be changed without affecting the preload of the keeper pin biasing spring. It is simple inconstruction and in operation for the result achieved thereby. It is relatively inexpensive to manufacture.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to'other features and subcombinations. This is contemplated by and is within the scope of my claims..lt is further obviousthat various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be understood that my invention is not to be limited to the specific details shown and described. Having thus described my invention, what my claim is: I

1. A self compensating adjustable keeper assembly for use with a latch operated to engage a keeper to move a member from an out-of-ho'me position on a support to a home position on said support including in combination, a keeper engaged by said latch, a twopart assembly mounting said keeper on said support, means fixedly securing one of said parts to'said support independently of said other part, means mounting said keeper on the other part for sliding movement from a retracted position to an extended position in response to operation of said latch, a spring biasing said keeper to said retracted position, and interengageable screw threads continuous around each of said first and second parts, said screw threads permitting relative rotary movement of said parts around an axis to an ajusted position of said other part relative to said fixedly secured part and of said keeper relative to said support prior to operation of said latch while preventing relative movement of said parts in response to an axial force to secure said parts to each other in a fixed relative position prior to' and independently of the operation of said latch. I

2. An assembly as in claim 1 in which said keeper is a pin having a longitudinal axis, said'mounting means mounting said pin for movement in a direction transverse to said axis.

3; An assembly as in claim 1 in which said connecting means comprises interengaging elements carried by said parts. I I

4. An assembly as in claim 1 in which said keeper is a pin, said mounting means comprising a bracket carrying said pin, a rod on said bracket, a head on said rod and a spring biased between said head and said one part.

I 5. A self-compensating adjustable keeper assembly for use with a latch operated to engage a keeper to move a member from an out-of-home position on a support to a home position on said support including in combination, a two part mounting assembly, interengageable screw threads continuous around each of said parts, means fixedly securing one of said parts to said support independently of said other part, a bracket, a keeper pin carried by said bracket engaged by said latch, a rod secured to said bracket, a head on said rod, and a spring biased between said head and said other part urging said bracket toward said support, said screw threads permitting relative rotary movement of said parts around an axis to an adjusted position of said other part relative to said fixedly secured part and of said keeper pin relative to said support prior to operation of said latch while preventing relative movement of said parts in response to an axial force to secure said parts to each other in a fixed relative position prior to and independently of the operation of said latch.

6. A latch. and keeper assembly for moving a chassis along a rack from an out-of-home position to a home position in response to operation of said latch to engage said keeper including in combination, a bracket, a keeper pin carried by said bracket, a two part bracket support, interengageable screw threads on said parts means fixedly securing one of said parts to said rack independently of the other part, a rod on said bracket, said rod carried by the other part for sliding movement thereon, a head on said rod, a spring biased between said head and said other part biasing said pin to a retracted position, a lever having a hook at one end thereof, means mounting said lever on said chassis for pivotal movement around a point intermediate its ends between a first position at which it engages said keeper pin and a second position out of engagement with said keeper pin, and interengageable means on the other end of said lever and on said chassis releasably holding said lever in said first position, said screw threads permitting relative rotary movement of said parts around an axis to an adjusted position of said other part relative to said fixedly secured part and of said keeper pin relative to said support prior to operation of said latch while preventing relative movement of said parts in response to an axial force to secure said parts to each other in a fixed relative position prior to and independently of the operation of said latch. 

1. A self compensating adjustable keeper assembly for use with a latch operated to engage a keeper to move a member from an outof-home position on a support to a home position on said support including in combination, a keeper engaged by said latch, a twopart assembly mounting said keeper on said support, means fixedly securing one of said parts to said support independently of said other part, means mounting said keeper on the other part for sliding movement from a retracted position to an extended position in response to operation of said latch, a spring biasing said keeper to said retracted position, and interengageable screw threads continuous around each of said first and second parts, said screw threads permitting relative rotary movement of said parts around an axis to an ajusted position of said other part relative to said fixedly secured part and of said keeper relative to said support prior to operation of said latch while preventing relative movement of said parts in response to an axial force to secure said parts to each other in a fixed relative position prior to and independently of the operation of said latch.
 2. An assembly as in claim 1 in which said keeper is a pin having a longitudinal axis, said mounting means mounting said pin for movement in a direction transverse to said axis.
 3. An assembly as in claim 1 in which said connecting means comprises interengaging elements carried by said parts.
 4. An assembly as in claim 1 in which said keeper is a pin, said mounting means comprising a bracket carrying said pin, a rod on said bracket, a head on said rod and a spring biased between said head and said one part.
 5. A self-compensating adjustable keeper assembly for use with a latch operated to engage a keeper to move a member from an out-of-home position on a support to a home position on said support including in combination, a two part mounting assembly, interengageable screw threads continuous around each of said parts, means fixedly securing one of said parts to said support independently of said other part, a bracket, a keeper pin carried by said bracket engaged by said latch, a rod secured to said bracket, a head on said rod, and a spring biased between said head and said other part urging said bracket toward said support, said screw threads permitting relative rotary movement of said parts around an axis to an adjusted position of said other part relative to said fixedly secured part and of said keeper pin relative to said support prior to operation of said latch while preventing relative movement of said parts in response to an axial force to secure said parts to each other in a fixed relative position prior to and independently of the operation of said latch.
 6. A latch and keeper assembly for moving a chassis along a rack from an out-of-home position to a home position in response to operation of said latch to engage said keeper including in combination, a bracket, a keeper pin carried by said bracket, a two part bracket support, interengageable screw threads on said parts means fixedly securing one of said parts to said rack independently of the other part, a rod on said bracket, said rod carried by the other part for sliding movement thereon, a head on said rod, a spring biased between said head and said other part biasing said pin to a retracted position, a lever having a hook at one end thereof, means mounting said lever on saId chassis for pivotal movement around a point intermediate its ends between a first position at which it engages said keeper pin and a second position out of engagement with said keeper pin, and interengageable means on the other end of said lever and on said chassis releasably holding said lever in said first position, said screw threads permitting relative rotary movement of said parts around an axis to an adjusted position of said other part relative to said fixedly secured part and of said keeper pin relative to said support prior to operation of said latch while preventing relative movement of said parts in response to an axial force to secure said parts to each other in a fixed relative position prior to and independently of the operation of said latch. 